<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <h1 id="time">10</h1>
    <script>
        // 从10开始倒计时
      let daojishi = 10;
      let h1 = document.querySelector("#time");
      id=setInterval(function () {
        daojishi--;
        h1.innerText = daojishi;
        if(daojishi===0){
            clearInterval(id)
        }
      }, 1000);
    </script>
  </body>
</html>
